Texas Instruments: Driving GaN FETs becomes reality

Texas Instruments: Driving GaN FETs becomes reality

The National LM5113 is the industry’s first 100-V half-bridge gate driver optimized for use with enhancement-mode GaN power field-effect transistors (FETs) in high-voltage power converters. This is significant because GaN FETs have an absolute maximum gate-to-source voltage rating of 6 V. Any voltage above this value will damage the device. GaN FETs also have a low threshold voltage that could be triggered during transient events that, through PCB parasitic, could cause the device to prematurely turn on and cause damage. This device includes a low-impedance gate drive source, which helps to minimize this false triggering.

The device is a highly integrated high-side and low-side GaN FET driver that reduces component count by 75% and shrinks PCB area by 85% compared to discrete driver designs. The half-bridge gate driver meets the stringent requirements of enhancement-mode GaN FETs. Using proprietary technology, the device regulates the high-side floating bootstrap capacitor voltage at approximately 5.25 V to optimally drive eGaN power FETs without exceeding the maximum gate-source voltage rating. It offers independent sink and source outputs for flexibility of the turn-on strength with respect to the turn-off strength. A low-impedance pull-down path of 0.5 Ω provides a fast turn-off mechanism for the voltage, and features an integrated high-side bootstrap diode to further reduce PCB real estate. The device also provides independent logic inputs for the high-side and low-side drivers.

Texas Instruments
Dallas , TX
Information 800-477-8924
www.ti.com